Innate Behavior
by Delphox
Summary: The effects of knowing who you were born to love and protect, but having to convey those feelings to them without scaring them off. Natsu knows who his mate is, but how could he possibly tell her? Would she reject him?
1. Chapter 1

Brows furrowed, stomach in knots, I waited. I remained perched on her windowsill for moments just wondering if I would be able to pull off another day like this – another day hopelessly in denial. Her scent overwhelmed me in the most wonderful way possible. It lulled and calmed my unnerved senses; but it also made me restless. How could I sit here, plain as day, and deny what I knew was happening? How I knew I felt? Every inhalation of her scent was just another breath of sweet torture. I could feel my canines aching in want. My instincts pulsed through my body and I felt my fists clen…

"Natsu!" I looked up, a sincerely shocked expression plastered on my face. "What have I told you about climbing in through my window? Why can't you just use the door? How many times do I have to….."

She droned on and on, but I really just couldn't bring myself to mind. I threw a grin on my face and cut into her rambling, "Good to see ya, too, Lucy!"

The great thing about Lucy was that no matter what sort of torment I seemed to be going through on the inside, she always snapped me out of it – in one way or another. It did occur to me that I may not get off so easily this time.

I hopped off the ledge of her window and quickly made myself comfortable on her couch. As I landed comfortably on the cushion, a sudden rush of air flooded Lucy's scent to my nostrils. My eyes widened as I felt a warmth spread through my chest. I inhaled quickly and turned my head, hoping Lucy wouldn't notice.

"Hey, are you feeling ok?" she questioned, bending slightly and tilting her head in an attempt to look at me closer.

" 'Course!" I smirked, not missing a beat. "Never better."

"Well, if you say so…" she shrugged, "Why are you here anyways?" she raised an eyebrow and pulled a face. She's probably trying to seem annoyed, but I know her better than that.

"Actually, I grabbed us a mission from the guild!" I reached into my pocket and showcased the flyer reading, "Bring back my artifact – 450,000J"

"Wow, not a bad find, Natsu! It doesn't even look that hard."

Hearing her praise made a wave of that strange warmth surge through me again. I reveled in it, yet knowingly feared it. I wanted to purr, but I wanted to run away. What if I hurt her? I couldn't possibly live with myself knowing…

"Yo, Natsu, you're scaring me again."

It was then that I realized I had been staring – straight into her eyes – I could feel the tense expression I wore and forced the crease between my eyebrows to go lax.

I gave a nervous laugh, "Sorry, Luce."

The ride into the city was smooth, considering Lucy let me lay in her lap for most of the ride. As soon as I felt the train come to a halt, I jumped to my feet, invigorated by the thought of getting off this satanic train.

"Let's gooooooooooo!" I pumped my fists and turned back to see if Lucy was following, sparks of flames escaping my mouth.

We followed our employer's directions, trailing all the way to his small, old-style cottage on the edge of town. Lucy, being the more polite of the two of us, gently tapped on the door.

"A-ah… ahem… come in!"

Lucy turned her head just enough to be able to see me over her shoulder and shoot me a glance that said, "what". My eyes widened slightly and I shrugged. Lucy simply sighed and pushed the door open, revealing a short, older man with a genuine smile and a white beard that told of age. A closer glance exposed the worry behind his smile; I could smell the anxiety wafting around him.

"Thank you… so much… for accepting this job." The man started. "My name is Pachy and I'd be happy to set some tea if you'd like..?"

"That won't be necessary, sir." Lucy offered a small and honest smile. She could no-doubt feel the troubles this man was dealing with – even without a dragon's senses. Another alluring characteristic of Lucy, I thought, smiling to myself as I unconsciously stepped closer to her.

"We're just here to get some info on this job so we can get it done as quickly as possible for you." Lucy continued.

Old man Pachy gave another earnest, yet pained, smile and began.

"Alright… The artifact that I need you to retrieve is named 'Fortune's Eye'. It's a small orb that can guide its owner to happiness." Pachy's sad smile faltered for a moment and he sighed before continuing, "This orb is a family heirloom that I passed to my only daughter when she moved away… She was killed just recently; bandits found out she had the orb and they took it by force." By the end, Pachy's voice had cracked and he looked away.

I felt Lucy tense up. She reached out for him, placing her hand gingerly on the man's back in an effort to comfort him.

Pachy shook his head, "Please, take out this group and bring the Eye back to me." He looked at the two mages with a mixture of determination and sadness.

Walking down the wide, dirt road, Lucy and I made our way deep into the forest – where the bandits were supposedly set up. It was easy enough to smell the distraught air around Lucy. Given how my instincts had tied my emotions to hers, I felt myself grow somewhat troubled.

The road was almost eerie; there was a dense forest bordering the path on either side, with no other travelers or signs of life in the area. This only encouraged me to stay alert. With my mate so open and exposed, I couldn't afford to be caught off guard. My train of thought was slightly derailed when I noticed her step closer to me as we walked.

_She must be scared_, I thought. I puffed my chest out and smirked at the thought.

"Hey, Natsu?"

I quickly looked at her.

"Are you sure we shouldn't have brought Erza and Gray with us?"

I snorted, "No way! I can take this whole gang by myself if I have to!" My mouth spurted flames as I spoke, my excitement also shown by a huge, fang-bearing grin.

Lucy gave a quiet laugh from beside me, a smile fighting to show through, but she looked down, and that worried me.

"Lucy." I almost whispered.

Her gaze immediately shifted back to me.

"I'll take care of you."

I meant the words too much to be embarrassed by them.

A shocked expression slipped across her features for only a split second before being replaced by a genuine smile and a soft tinge of pink on her cheeks. I felt my breath catch as I offered a grin back.

_That's it_, I thought, _I'm going to have to tell her. _Thinking a little more, I realized I wasn't exactly the best with words.

_I'll show her. _I decided. _Soon._

I could sense that Lucy's stress from before had mostly dissipated. This, in turn, calmed me.

As we continued down the road, another scent, far less alluring than Lucy's, entered my system. I didn't want to startle Lucy, so instead, my eyes darted around us: into the trees, ahead and down the road. The smell soon became more potent, too potent to ignore.

"Lucy." I tugged her elbow, stepping in front of her protectively and growled, "Stay behind me."


	2. Chapter 2

Four bandits lay at my feet. With my foot perched on top of one, I pumped my fists into the air, letting out a triumphant laugh.

"C'mon, get up, that was too easy! Fight me again!"

Lucy sighed and made a face of mock annoyance. "Let's go, Natsu. There's probably plenty more where those guys came from."

The sound of her voice saying my name was all the convincing I needed. In a flash I was beside her.

"Let's go!" I couldn't help but smile.

We kept moving and soon I was bored, "We need to find this Fortune Cookie thing so I can fight some more." I pouted.

Lucy snorted a laugh and added, "Is that all you think about?"

"Of course not!" My pouting face turned to look at her. "I think about food, and the guild, and… and…"

_You._ I thought. _Mostly you._ I looked back forward and added, "… and other stuff."

Lucy rolled her eyes with a smile on her face, "You're so predictable."

All our walking finally paid off when a small fortress came into view. "Look!"

"Wait, Natsu, we need to think of a plan. There are probably tons of bandits guarding the entrance, we should scout out the sides and see if there's another way in – or at least a side that's less guarded than the others." She rambled on. By the time she noticed I was gone, I was already through the gate.

"Hey!" She fumed.

A maniacal laugh escaped my jaws as a hoard of bandits surrounded me. I could feel that many of them possessed little to no magic at all. The only thing they really had against me was sheer numbers. But what did that matter when I had a power like Igneel's in me?

Lucy let out a rather loud and annoyed groan, but quickly adapted. She climbed to the upper walkway of the fortress and wasted no time in summoning Sagittarius, who could shoot down multiple enemies at once.

As they began taking out the numbers who had swarmed me, I made my way to the only door in the fort. _They must be keeping the fortune tell-y thing-y in here! _I thought as I threw the doors open. Inside was a single room, lined with beds all the way around. It was obviously where the gang slept and rested. My attention was immediately drawn to a large staircase in the middle of the room, winding straight up to the next floor. I smirked, _Boss time._

Upon reaching the top of the staircase, I poked my head up through the opening just enough to see without being seen. I noticed several things. The first was that the eye was thrown casually on a small work desk on the side of the room. While the thought of killing an innocent person just to get some treasure enraged me to no end, I was _livid _at how _nonchalant _the item's placement seemed. The second thing that struck me was that the man who was obviously in charge here sat near a window, gazing out and watching his men being beaten with a completely uninterested air. Even I had the logic to know that if he had been looking out of that window, he knows I'm in the building.

As if on cue, his chair swiveled around and suddenly I was met with a pair of cold, bloodshot eyes. My brows furrowed as I stepped up and into the room. I could feel a spell of some sort nullifying my magic. I snorted, _If it's coming from this room, he won't be able to use any magic either._ I took a step forward, mentally preparing myself for hand-to-hand combat.

The man stood, sizing me up with his eyes, "What are you here for?"

My eyes flickered to the orb that lay clumsily on his desk. His eyes followed my own and, in annoyed understanding, he bellowed, "_That?_ You came all this way for that piece of junk?" I raised an eyebrow at the man. "It doesn't even work, I tell you… I went to all that effort… Put so much faith in something so worthless…"

"I don't give a rat's ass if it 'works' or not. You stole and _murdered_ for this thing and now we're taking it back." I seethed.

The man made a 'humph' noise and merely looked at me for what seemed like minutes. "Have it your way, then." He lurched towards me, but I quickly shifted to the side, avoiding the blow. In a flash, he turned and grabbed my shoulders, pushing me back. On instinct, I grabbed his and fought for control. Soon, we crashed into the area he had been sitting at. I had gained the upper hand, pushing him against the window with enough force to pin him there.

"Just give us the orb and we'll leave."

The man made an almost defeated, yet still rage-filled, expression. His grip on me tightened before he rotated, throwing all of his weight on me and sending us crashing through the window. A strangled noise escaped my lungs as the glass cut harshly into my back. The man and I released each other as we fell from the second floor. Blood had already started running down my arms. _Such pain…_

"Natsu!"

My eyes squinted open and when they met Lucy's something in me both snapped and awakened.

_She still needs me_, the thought flashed across my mind.

Not a second later and my body crashed painfully into the dirt. My face twisted from the throbbing now emitting from my back. The shock had worn off and now the pain was seeping through. I inhaled quick, sharp breaths and slowly rose to my feet, slumping over from the effort it took. I looked to my right; the man from before lay unconscious only a yard or so over. To my left, Lucy and Sagittarius had taken out almost all of the bandits. I felt a tinge of pride at how powerful Lucy had become, but decided I needed to focus on other things right now.

I turned and staggered back up to the room, grabbed the orb, and returned to the fight outside feeling very, _very_ unstable. Lucy had just finished wiping out the rest of the lackeys and closed Sagittarius's gate. The moment she saw me, her face scrunched with worry and she ran over.

"Natsu!" She held one hand at my back, twisted into my blood-soaked vest in an attempt to help me stand. The other was griping my arm tightly.

"It's ok, Lucy." I drawled out in an almost drunken state. My head felt so light that I couldn't stand. I staggered forward, my face falling in between her neck and shoulder, my arms hanging limp. The last thing I could remember was her hands in my hair.


	3. Chapter 3

Cringing, I awaken in a haze: a massive headache pounds in my ears, my body's weight feels doubled. A sweet scent wafts in the air and I roll my head groggily to the right. My eyes widen in affection at the sight of a certain blonde sitting beside the bed, her arms folded on top of it, with her head resting face-down on them. She was mere inches from me and I suddenly wondered how long I had been here.

Looking around, my surroundings seemed vaguely familiar. The furniture, the smell – it reeked of an old man. _Old man Pachy's house? _I concluded.

I noticed my top had been removed and replaced by bandages wrapped around my chest. I was abruptly aware of a dull throbbing emanating from my back – almost as if it had been sedated.

"Lucy…" I breathed.

When she didn't respond, I reached out for her, latching on to her wrist and giving her a light shake.

"Luuucyyyy…" I whined, my eyebrows scrunching together in a pout.

She groaned and let out a deep exhale, slowly raising her head. A look of shock and realization crossed her face and suddenly her arms were around me.

"You're… okay…" She choked out. "You lost so much blood… it was everywhere… and… and…"

My eyes widened at how affected Lucy was by _my _injuries. Did she even notice her own? I sure as hell did. The scent of Lucy's blood had always burned my nose. My heart wrenched at her display of emotions and something tugged within me. I wrapped my arms tightly around her and buried my nose in her hair, eyebrows knotted together.

"Lucy I-"

"Ah..! You're finally awake!" Pachy had entered the room.

Lucy flinched in surprise and, to my dismay, quickly untangled herself from me.

I rolled my head to face the old man and flashed a smile that was probably only half as bright as usual.

Pachy shook his head in awe, the tiniest smile playing on his lips. "You two are really something." He stated, motioning over to the orb now sitting in a rather beautiful display case. It was obvious how much this had meant to Pachy by how carefully the orb had been stored in its case and placed on the shelf. This thought made my smile grow.

"However," he looked deep in thought, "I just don't feel like money is enough to repay you." Another small smile brightened his features, "So I'd like you to have Fortune's Eye."

Lucy immediately spoke up, "We couldn't take that from you! It's a family heirloom – I'm sure it's priceless."

"Yes, well… With my daughter gone, it's not like I have anyone to pass it on to…" His eyes closed bitterly. "And the sight of it only reminds me of what happened to her."

Lucy's features radiated sadness but she seemed to understand. Pachy looked to me and I simply nodded.

"I will never forget you two."

The trip back to Magnolia was long and agonizing. I couldn't lie on my back because of my injuries, but lying on my stomach increased my nausea tenfold. In a word, it was hell.

Lucy insisted I stay at her place for a while so she could treat my wounds. She seemed to feel guilty about what happened – like it was her fault. I felt a little bad about that, but, if it meant I'd be with her for the next few days, I wasn't really complaining.

Before we left, the old man ended up explaining how the orb worked. He went into too much detail for my taste but, by the end, I understood the concept of it.

The orb didn't simply function just by being in someone's possession – you had to activate it. It was pretty easy to do, he said, as all you really needed was a pure heart and good intentions. He continued by saying that the original creators forged the sphere well-knowing that a person with evil intentions could easily take hold of this and cause some serious anarchy. This is why the orb's magic penetrates into both your heart and mind; it passes judgment based on what it finds, then instills or awakens the emotions you need to find or fulfill yourself.

I didn't think we'd ever use it too much, considering its effects were limited to your own emotions and I'd say we're both pretty happy.

I grinned at the thought, glancing at Lucy who had finished dressing my back and was now wrapping more bandages tightly around my abdomen. As I waited patiently for her to finish I thought about how _good _her fingers felt brushing against my bare chest.

_Really_ good.

My jaw locked as I bit back a growl.

Wait… the hell? _It's not even "season" yet_, I thought frantically. _It's just… now… _My gaze dropped to stare unblinkingly at the floor.

_Spring…_

_Shit._ That meant the inevitable. Never before had I actually _found_ my mate. Igneel had only ever _warned _me about this. I never thought this kind goopy crap would actually happen to me.

_Aw, man…_ My mind raced erratically. _I don't have that much time. _I was hoping to be able to show Lucy how I felt before it got to this point but I guess I _may_ have procrastinated a little.

I began to panic. Now that spring is here, it won't be long until the symptoms start. Aggressiveness, obsession, getting caught up in her – I can still remember the way Igneel described a dragon's mating season: as if it were the most beautiful process imaginable. Yet, here I sit, my mate so close I can hear the blood pumping through her veins – she's even _touching _me, dammit – and all I can feel is afraid.

And… excited? Shit.

"Natsu," she called. "You okay? You look like you can't breathe." She teased, her eyes sparkling in amusement.

Wait... No. Since when do I notice the way her eyes sparkle?

I guess if I'm being honest, I've noticed for a long time; it took me a much longer time before I _knew_. And now, as I stared her straight in the eyes, my mouth ajar and our faces mere inches apart, I realized just what my downfall would be: awareness.


	4. Chapter 4

~switching to third person, forgive meeee~

Natsu stared at her. And stared at her some more. And stared at her some more. And-

Morning had come. Lucy had let him take the bed because of his injuries. She told him: "I can handle the couch for a few days, I'm not a BRAT!" He sent her a sly smile at the comment, at which Lucy nearly ended his life. Yet, as his eyes adjusted to the light, she was there, curled neatly beside him. Across the room, the orb pulsated. Natsu's eyes slitted and sharpened as they quickly studied the object.

Did he imagine it? 'Couldn't have.

Seconds passed. At last Natsu decided whatever it was, it was no immediate danger. He let his gaze fall again to his partner, his heart swelling as gentle puffs of air escaped her.

"Got scared last night and needed ME to protect ya, huh?"

"Hell no."

"AEEEEEEE-" He released a high pitched scream and tumbled out of the bed.

"This is just comfier." Her head peaked over the side of the mattress, a carefree smile sent his way.

Lucy's playful mood, her damn smile. Ba-dump. A flash of light from the orb.

"Huh?" Lucy's head turned.

Breathing became difficult. An unbearably addictive scent took over his nose.

"Why are you breathing so-" As her eyes met his, her voice dropped in awe.

"Natsu..." His eyes were a beautiful blood red. His gaze held what felt like adoration and desire and... love? She was captivated. As if he was calling her like a siren with only his gaze. With a grunt, Natsu's hand gripped the edge of the mattress, rising slightly towards her. Their eyes were locked; his gaze did not faulter. Lucy's fingers twitched in anticipation: finally!

Wait.

This can't be right.

A growl snapped her attention back. Those eyes were furrowed with a look even more intense than the last. The needy, harsh gaze pierced her.

She was scared.

Of Natsu.

Recognition flashed crimson eyes to onyx and in a second Natsu distanced himself.

"Gomen." His voice was quiet, an audible whisper. "You shouldn't have had to see that."

"Natsu... What was that?" Lucy stood as if to move towards him, but Natsu stepped back. "Lucy. I really need to talk-"

"Oh, I know!" She exclaimed.

His expression dropped, dumbfounded. How did she...?! How could she?! Did Levy have some ugly ass book on him in her library? Those dragon books are disgustingly accurate...

Well, he thought, this is embarrassing.

"Oh, don't be embarrassed, Natsu! Everybody gets sick!" A cheeky grin, as if she were being understanding.

"Yeah! Everybody gets a lil'... s-s-s-s-sick?!" He sputtered.

"Yep! The orb flashed and then you got all weird. It only makes sense, right? That must be it." She hammered one fist into her flat hand like she just made the discovery of a lifetime.

Natsu's mind was racing. Should he use this to avoid telling her... It seemed like the easiest way out.

He gave her a nervous laugh. "Yeah, maybe you're right, Lucy, I think I'm sick."

She beamed. "Of course!" She seemed frantic. "I should really get you some medicine. Is your tummy hurting? I'll be back in a few!" She grabbed her purse and hustled out the apartment.

Natsu sighed as the door closed. He let his guard down. He knew better. Heat had come and he let himself stay so close to her. She was so close. _So close._ He winced. He can't let this happen again. Keeping away from her would only hurt them both. He'd just have to be more careful. Or I could tell her, a voice in the back of his mind called. His teeth clenched. That's what he really wanted. _That's_ what would make him happy. In the end he knows he has to choose: to tell her or run. He knows he won't be able to last much longer around her. It'll become unbearable. He wants her.

His mind flashed. Back there. When he had lost control for those deliciously long seconds, he didn't have to hold back anymore. He looked at her with all the emotion he had bundled up inside of him and called out to her. He remembered. How she looked back at him. First shock. But then... she looked comfortable. Accepting. Would she accept him? Hope welled in him.

Lucy slid down her door. While laying in the hall of her apartment complex wasn't her favorite thing in the world, Lucy found herself just trying to catch her breath. Her heart was pounding. She felt... unnerved to say the least. What was wrong with Natsu? That was no common cold, that's for sure. Was he ok? What was with that look he was giving her? What's more: why did it make her feel so _good_. She put a hand to her chest, feeling her heart hammer uncontrollably. She was used to getting flustered around Natsu sometimes, let's be real, she was crazy about him. She'd never dropped the L-bomb before, but if it had been saved for anyone, it was him. She knew it was him. She had always thought his carefree density was charming, but what she just experienced in there was a whole new world. She'd never seen Natsu look at anything the way he'd just looked at her. Like he wanted to protect her using his own body as a shield but also rip her clothes off. She needed to talk to someone, and if there was anyone who'd have the resources she needed, it was Levy.


End file.
